Method for dispensing a solution

ABSTRACT

A method of using a fluid injector in fluid communication with a fluid flow line where flow is transferred from the flow line into the fluid injector and back to the fluid flow line. An inlet flow is used to pressurize the storage tank and provide a solution to mix with injection solutions in the tank.

RELATED APPLICATION INFORMATION

This application is a continuation of and claims the benefit of U.S.patent application Ser. No. 10/173,284, filed Jun. 17, 2002 now U.S.Pat. No. 6,546,949 which, in turn, is a continuation of and claims thebenefit of U.S. patent application Ser. No. 09/895,629, filed on Jul. 2,2001, now U.S. Pat. No. 6,453,935 both of the same title.

FIELD OF INVENTION

This invention relates to storage tanks and fluid injection systems,specifically to injection metering devices.

BACKGROUND

A variety of means have been used to inject fluids into fluid streams.These include metering pumps, water powered pumps, siphon devices, flowthrough devices and gravity feed drainage equipment.

There are a number of problems encountered with each type of equipmentavailable in delivering an accurately proportioned injection amount.Metering pumps are either set to inject a predetermined amount into afluid stream without a means of adjusting to changes in flow volume inthe fluid stream, or they are controlled electronically by flow sensorslocated in the fluid stream. The components of this type of system aremechanical and electronic so they are subject to wear and mechanicalfailure. Water powered pumps adjust automatically to changes in flow inthe fluid stream but are a mechanical device with a number of sealpoints. The seals require frequent maintenance for the unit to operateproperly. This design is limited in the amount of fluid flow it canoperate with and as flows increase, the cost of the device increases.Siphon devices rely on a high restriction in the fluid stream to createventuri suction strong enough to pull the injection solution from thestorage container. They require high pressure to operate and the highrestriction in the fluid stream greatly reduces the fluid stream volume.Fluctuations in pressure can cause the device to not inject continuouslycreating uneven distribution. They are also unable to dependably injectsolutions such as water-soluble fertilizers without plugging. Venturisystems generally have relatively small flow orifices and the fertilizersolution has a tendency to settle, creating sedimentation that plugsthese orifices. Flow through devices typically channel the flow of thefluid stream through a container that holds a soluble product thatslowly breaks down, releasing the product into the stream. This methoddoesn't control the amount being distributed and can give unreliabledistribution. It is common for the soluble products to melt as they sitin the water while the system is not operating and release a largeamount when the system is restarted.

Several types of fluid injectors have been developed to proportionliquid or soluble fertilizers or chemicals into fluid piping systems. MyU.S. Pat. No. 5,484,106, Automatic Pressurized Adjustable SolutionDispenser accomplishes this task but relies on a check valve to preventback flow of contaminants into the fluid stream. With this design, theoutlet flow port connection needs to extend to the bottom of the storagetank to establish a consistent injection rate of fertilizers, which havea higher specific gravity than the incoming water. When the outlet portconnection is extended to the bottom of the storage tank, the systemdevelops an air pocket in the top of the storage tank that can only beeliminated by manually filling the tank with fluid or some other meansof manually venting the system. If the air is not removed from thesystem, a potentially hazardous condition exists in that air compressesunder pressure, which creates a higher stress on the storage tank thanfluids under pressure and can cause the storage tank to rupture at muchlower operating pressures. The presence of air also reduces the amountof fluid in the storage tank. This limits the fluid available to mixwith soluble products to make them an injectable solution, causing thesystem to not inject accurately or possibly not inject at all due toplugged flow ports. Since there is no way for air to escape the storagetank, soluble products must be premixed and the tank filled with waterbefore using the system. Many soluble products begin settling to thebottom of the tank immediately after being mixed. Continual agitation isrequired to keep them in an injectable state. This requires extendingthe inlet port near the bottom of the storage tank to direct flowthrough the soluble product. Also, this design does not provide a meansof injecting more than one solution from the same tank at independentratios.

The U.S. Pat. No. 4,846,214, Fluid Additive Injector by Thomas F. Stronghas an automatic mechanical air relief valve that vents air from thestorage tank to the atmosphere. While it does evacuate the air from thetank automatically, it is mechanical in nature so it is subject to wearand eventual failure. It does not provide back flow protection,establish proportioning rates or allow air to be vented through thepiping system. It also does not provide a means of injecting more thanone solution from the storage tank at independent ratios.

The U.S. Pat. No. 3,809,291, Liquid Proportioning System by Chester A.Purdy is a gravity feed system that uses an internal mixing chamber tocombine two liquids to be dispensed into a fluid stream. It requires anelectrical controller, a pressure switch and a float valve to controlfluid flow into the tank.

The U.S. Pat. No. 5,544,810, Precision-Ratioed Fluid-Mixing Device AndSystem by Horvath, Abrams and Helf utilizes a high pressure flow line tocreate a venturi to draw multiple fluids from multiple unpressurizedcontainers and accurately mix them into one solution. The system has anair vent to the atmosphere to prevent siphoning of fluid from thestorage containers when the system is not operating. This designrequires a high-pressure flow line to create enough vacuum to drawfluids from the containers. This creates a high restriction in the flowline, significantly reducing flow volume and pressure. It also requiresmultiple containers to store the various solutions, which requirespiping connections between all the containers used. This design cannotoperate at low pressures or automatically mix dry products and keep theman injectable solution.

The U.S. Pat. No. 6,039,065, Fluid Proportioning Valve And Method byJohn P. Gagliardo is mixing valve that combines liquids at controllableproportions. It does not provide for the injection of liquids into aflow line, only the mixing of incoming flows.

My invention solves a number of problems that have been present in priorart. It eliminates the need for a mechanical check valve and air reliefvalves, which are subject to wear, leakage and failure. It operates atvery low pressures without the need for restriction in the flow line. Itoperates totally on pressure from the flow line and injects veryaccurately. It can handle dry products as well as very heavy productswithout plugging or manual mixing. It can inject multiple solutions atindependent injection rates from one storage tank.

OBJECTS AND ADVANTAGES

Accordingly, the objects and advantages of my invention are:

(a) Provides the ability to accurately inject one or more liquidsolutions into a fluid stream at independent injection rates.

(b) Soluble products can be put in the storage tank dry and the systemwill exhaust all air from the storage tank while mixing the productsautomatically, eliminating manual mixing and plugging.

(c) Provides back flow and siphoning protection with the need formechanical check valves and air relief valves, which makes the systemmore dependable, less expensive to manufacture, have a longer servicelife and require less maintenance.

(d) Flow control allows a wide range of injection rates, which gives theuser the ability to apply the products in minutes or over weeks ormonths.

(e) Highly concentrated product can be used, which reduces storagerequirements.

(f) There are no moving parts to wear out or break. All operations arecontrolled by system flow.

(g) Little exposure to hazardous chemicals. The chemicals can be appliedin very low amounts automatically, which eliminates any exposure duringthe application process as well as better absorption rates, reducingnegative environmental impact.

(h) Mixing incoming fluid with the outgoing solution makes the injectionrate slower so flow ports can be made larger which allows more fluidthrough the system, which prevents plugging, improves mixing andimproves injection accuracy.

(i) Inlet connections can be extended to the bottom of the tank toprovide agitation of soluble or heavy products, which keeps them in amore injectable state and eliminates the need for manual mixing when thesystem is initially filled. It also allows a higher concentration ofproduct to be put in the storage tank.

(j) Outlet connections can be extended to the bottom of the tank toprovide consistent, accurate metering of the injected solution.

(k) Provides a consistent injection stream so the injected solution ismore evenly mixed in the flow line.

(l) Operates a very low flow rates and pressures with no restriction onthe flow line pressure or volume, giving it a broad range of use in manyapplications.

(m) Responds to the smallest changes in pressure or velocity in the flowline, making it very accurate in all applications.

(n) Convenient emptying and filling of single or multiple solutions.Still further objects and advantages will become apparent in the ensuingdrawings and descriptions.

SUMMARY

In accordance with the present invention a fluid injector withvent/proportioner ports comprises a fluid injector that utilizes fluidfrom a flow line to accurately inject fluids into the flow line. Thesystem mixes incoming fluid with outgoing injection solution to providea wide range of flow adjustment. It uses flow orifices to provide airrelease from the storage tank as well as provide back flow protection.It utilizes multiple bladders to inject multiple solutions from onestorage tank.

DRAWING FIGURES

In the drawings, closely related figures have the same number butdifferent alphabetical suffixes.

FIG. 1 shows an overview of the system operating and how it is connectedto a fluid flow line.

FIG. 2 shows an overview of the system operating during back flowconditions.

FIG. 3 shows an overview of the system operating during back flow withvacuum conditions.

FIG. 4 shows an overview of the system with multiple bladders.

REFERENCE NUMERALS IN DRAWINGS

 1 fluid flow line  2 inlet connection tube  3 inlet vent/proportionerport  4 outlet vent/proportioner port  5 agitation tube  5a agitationnozzle  6 pickup filter  7 pickup tube  8 crossover connection  8amixing valve  9 outlet connection tube 10a tap fitting 10b tap fitting11 tank inlet connection 12 tank outlet connection 13 storage tank 14tank inlet port 15 tank outlet port 16 storage tank cap 16a bladder 16bbladder 17 site tube 17a fill port 17b fill port 17c fill port 18 drainvalve 19a fill port valve 19b fill port valve 19c fill port valve 20flow direction 21 injection solution 22 injection solution 23 fluid fromflow line 24 injection solution 25 air

DESCRIPTION

FIGS. 1, 2, 3—Preferred Embodiment

A preferred embodiment of the fluid injector with vent/proportionerports is shown in FIG. 1. This side view shows a basic view of theinvention and how it connects to a fluid flow line. The system can bemanufactured from various types of plastic, metal or both. Plasticconnections can be glued or threaded. Metal connections can be threaded,welded or braised. The tank inlet connection 11 is connected to fluidflow line 1 by attaching inlet connection tube 2 to tapping fitting 10a. The tank outlet connection 12 is connected to fluid flow line 1 byattaching outlet connection tube 9 to tapping fitting 10 b. The tankinlet connection 11 is connected to tank outlet connection 12 bycrossover connection 8. Mixing valve 8 a is located in the crossoverconnection 8, between tank inlet connection 11 and tank outletconnection 12. The tank inlet connection 11 is attached to tank inletport 14, which is attached to inlet vent/proportioner port 3 andagitation tube 5. Agitation nozzle 5 a is attached to the end of theagitation tube 5, which extends into the bottom portion of storage tank13. The tank outlet connection 12 is attached to the tank outlet port 4,which is attached to outlet vent/proportioner port 4 and pickup tube 7.Pickup filter 6 is attached to the end of pickup tube 7, which extendsto the bottom of storage tank 13. Site tube 17 is located in the outletconnection tube 9 between tank outlet connection 12 and tap fitting 10b.

Operations—FIGS. 1, 2, 3

The method of using the fluid injector with vent/proportioner ports isto connect it to a fluid flow line as shown in FIG. 1.

Once the unit has been installed, shut off all flow in the fluid flowline 1. Remove the inlet connection tube 2 and outlet connection tube 9from the storage tank cap 16. Remove the storage tank cap 16 from thetank and add the material to be injected, to the storage tank 13. Putthe storage tank cap 16 on the tank and attach the inlet connection tube2 and outlet connection tube 9 to the storage tank cap 16. Adjust themixing valve 8 a to desired injection rate and turn on flow in fluidflow line 1.

When the system is operating, a positive pressure is created by tapfitting 10 a creating fluid flow from fluid flow line 1, which isdirected through the inlet connection tube 2 to tank inlet connection11. The fluid is then directed through crossover connection 8 to thetank outlet connection 12 and through an inlet port 14 to storage tank13. The amount of flow to each area is controlled by mixing valve 8 a.As mixing valve 8 a is opened, more fluid flows through crossoverconnection 8 and less fluid through tank inlet port 14. This reduces theamount of fluid leaving the storage tank 13 which reduces theconcentration of the fluid injected into the fluid flow line 1. Thefluid entering the storage tank 13 through tank inlet port 14 flowsthrough inlet proportion/vent port 3 determines the amount of flowdiverted to the top and bottom of the storage tank 13. This controls theamount of agitation action directed at injection solution 24. Thebalance of the fluid entering the storage tank 13 is directed throughthe agitation tube 5, through agitation nozzle 5 a, into the bottom ofthe tank and into the injection solution in the bottom of the tank. Bydirecting the inlet flow to the bottom of the tank, dry soluble productsare mixed automatically with inlet fluid from fluid flow line 1 as thestorage tank 13 is filling. The air in storage tank 13 is exhaustedthrough outlet vent/proportioner port 4 into the fluid flow line 1.Since air moves more easily than liquid, no fluid leaves the storagetank 13 until all the air has been exhausted. This provides thoroughmixing of injection solution 24 which creates accurate injection andprevents plugging.

Flow entering storage tank 13 pressurizes storage tank 13 to the samepressure as the fluid flow line 1. A negative pressure is created by tapfitting 10 b creating flow from storage tank 13. This flow is directedthrough pickup filter 6 through pickup tube 7 as well as throughvent/proportioner outlet port 4 to tank outlet port 15. The size of thevent/proportioner outlet port 4 determines the mix ratio of fluid insidethe storage tank 13 and injection solution 20. It then flows throughcrossover connection 8, where it mixes with inlet flow and then flowsthrough tank outlet connection 12 to tap fitting 10 b through outletconnection tube 9.

Tap fittings 10 a and 10 b do not create any restriction in flow line 1.Because the storage tank 13 is pressurized to the same pressure as flowline 1, any changes in flow line 1 pressure or velocity is communicatedto storage tank 13 immediately, making the system very responsive tochanges in flow and very accurate. This also enables the system to beginoperating with as little as two gallons per hour flow in fluid flow line1 and at as little as 5 PSI operating pressure. The system has nocapacity or volume restrictions. If flow restriction is put between tapfitting 10 a and tap fitting 10 b, the operating range is increased. Itcan be adapted to any size application. Because the flow through thesystem is consistent, not pulsating, the injection solution 24 enteringthe fluid flow line 1 is consistent throughout the fluid flow line 1solution.

When the system is operating, injection flow can be seen through sitetube 17. When material is no longer visible in site tube 17, the systemis empty and ready for refill.

FIG. 2 shows the flow pattern when a back flow condition exists. Tocreate a back flow condition, pressure is lost in fluid flow line 1 soany fluid in the fluid flow line 1 reverses direction. This reverses theflow through the system by creating a positive pressure at tap fitting10 b. This directs flow into the storage tank through the fertilizeroutlet tube 9, the tank outlet connection 12 and then through the tankoutlet port 15 and crossover connection 8. The adjustment valve 8 asetting determines the amount of fluid that reenters the storage tank.The more open the mixing valve 8 a is set, the more fluid that willbypass the storage tank 13 and return to the fluid flow line 1 throughthe inlet connection tube 2. The fluid that does not go through thecrossover connection 8 will flow into the storage tank 13 through thetank outlet port 15. This directs the fluid to the top of the tank andback out of the tank through the vent/proportioner inlet port 3. Sincethere is a loss of pressure in a back flow condition, there is much lessflow in the fluid flow line 1. This enables the vent/proportioner ports3 and 4 to handle all incoming and outgoing flow, preventing any toxicmaterial from the bottom of the tank from entering the fluid flow line1.

FIG. 3 shows how the system operates when all the fluid has beeneliminated from the fluid flow line 1. The fluid is replaced by airwhich creates a vacuum condition. The air follows the same flow path asthe fluid does during back flow conditions. Once air has entered thestorage tank 13 through tank outlet port 4, it flows through the inletvent/proportioner port 3 to the fluid flow line 1. Because air flowsmore easily than fluid, only air flows through the system. This puts thesystem in an air lock condition which prohibits any liquid from leavingthe storage tank 13.

To refill the unit, shut off all flow in the fluid flow line 1. Relievepressure from the storage tank 13 by opening a valve downstream in thefluid flow line 1 or by slowly removing the outlet connection tube 9from the storage tank cap 16. Once pressure has been relieved, removeinlet connection tube 2 and outlet connection tube 9 from the storagetank cap 16. Remove the storage tank cap 16 from the tank and pour outthe fluid in the storage tank 13. Add the material to be injected, tothe storage tank 13. Put the storage tank cap 16 on the tank and attachthe inlet connection tube 2 and outlet connection tube 9 to the storagetank cap 16. Adjust the mixing valve 8 a to the desired injection rateand turn on flow in fluid flow line 1.

FIG. 4—Additional Embodiment

An additional embodiment is shown in FIG. 4. It shows the addition ofbladder 16 a and 16 b. Bladder 16 a is connected to vent/proportionerport 4 a that is connected to tank outlet port 4. Bladder 16 b isconnected to vent/proportioner port 4 b that is connected to tank outletport 4. Fill port 17 a is connected to bladder 16 a. Fill port 17 b isconnected to bladder 16 b. Fill port 17 c is connected to storage tank13. Drain valve 18 is connected to storage tank 13. Fill port valve 19 ais connected to fill port 17 a. Fill port valve 19 b is connected tofill port 17 b. Fill port valve 19 c is connected to fill port 17 c.

FIG. 4—Operations

The method of using the fluid injector with vent/proportioner ports asshown in FIG. 4 is to turn off all flow in fluid flow line 1. Relievesystem pressure by opening a valve downstream in the fluid flow line 1.When the pressure is relieved, close the valve. Drain all fluid fromstorage tank 13 by opening drain valve 18 and fill port valve 19 c. Whenall fluid has been drained from storage tank 13, close drain valve 18.Open fill port valve 19 a and pour injection solution 21 into bladder 16a. When the desired quantity of injection solution 21 has been pouredin, close fill port valve 19 a. Open fill port valve 19 b and pour thedesired amount of injection solution 22 into bladder 16 b. When thedesired quantity of injection solution 22 has been poured in, close fillport valve 19 b. Pour the desired amount of injection solution 22 hasbeen poured in, close fill port valve 19 b. Pour the desired amount ofinjection solution 20 in fill port 17 c. When the desired amount ofsolution has been poured in, close fill port valve 19 c. Open the valveto allow flow into fluid flow line 1.

When the system is operating, fluid from the fluid flow line 1 entersthe storage tank 13 through the tank inlet port 14 and the crossoverconnection 8. The fluid entering the tank pressurizes the storage tank13, bladder 16 a and bladder 16 b. The negative pressure created by tapfitting 10 b along with the positive pressure created by tap fitting 10a create flow from bladder 16 a, bladder 16 b and storage tank 13.Bladder 16 a and bladder 16 b are made of flexible material thatcollapses as fluid is removed. They are used to contain injectionsolutions that need to be separated due to their reaction to othersolutions in the storage tank 13 or if their specific gravity is thesame or lighter than the fluid entering the storage tank 13 from thefluid flow line 1. As injection solution 21 leaves bladder 16 a andflows through tank outlet port 15, it is premised with fluid fromstorage tank 13 to a preset ratio determined by the orifice size of theoutlet vent/proportioner port 4 a. As injection solution 22 leavesbladder 16 b and flows through tank outlet port 15, it is premixed withfluid from storage tank 13 to a preset ratio determined by the orificesize of the outlet vent/proportioner port 4 b. All solutions leavingstorage tank 13 are then mixed with the fluid in crossover connection 8.Mixing valve 8 a sets the injection ratio for the combined solutionsbefore they enter fluid flow line 1.

SUMMARY, RAMIFICATIONS, AND SCOPE

Accordingly, the reader will see that the fluid injector withvent/proportioner ports will provide many advantages to consumers,industry and the environment. It provides an economical means ofaccurately injecting solutions that are normally difficult to inject. Itcan inject multiple solutions simultaneously into a flow line, each withtheir own injection ratio. Incompatible products can be combined in onetank and one installation. It is very easy to use and has a long servicelife with very low maintenance requirements. It easily adapts from smallto large applications. It can be manufactured easily and economicallyfrom products readily available in the marketplace. It can be fabricatedfrom plastic or metal piping components or molded.

While the above description contains many specificities, these shouldnot be construed as limitations on the scope of the invention, butrather as an exemplification of one preferred embodiment thereof. Manyother variations are possible. For example additional crossoverconnections with control valves could be added to provide specific flowadjustment for all solutions in the storage tank. The crossoverconnection and control valve could be eliminated and the proportioningrates set only by the vent/proportioner ports. The agitation tube couldbe removed for products that are lighter and easier to inject. Thesystem can accommodate filling and draining with ports sealed by valves,plugs or caps. The system can have the fluid flow line attach to it orhave it attach remotely. It can be designed to attach to the end of afluid flow line of any type.

Accordingly, the scope of the invention should be determined not by theembodiments illustrated, but by the appended claims and their legalequivalents.

What is claimed is:
 1. A method for dispensing a solution containedwithin a storage tank into a flow of fluid in a flow line, comprising:diverting a portion of the fluid from the flow line into a top portionof the storage tank; venting air from the top portion of the storagetank into the flow line as the storage tank fills with the portion ofthe fluid; drawing the solution from a bottom portion of the storagetank; and directing the solution drawn from the bottom portion of thestorage tank into the flow of fluid in the flow line.
 2. The method asrecited in claim 1, further comprising diverting a portion of the fluidfrom the flow line into a bottom portion of the storage tank to agitatethe solution.
 3. The method as recited in claim 1, further comprisingdrawing fluid into the flow line from the top portion of the storagetank during conditions of system backflow.
 4. The method as recited inclaim 1, wherein a positive pressure in the flow line is utilized fordiverting the portion of the fluid from the flow line into the topportion of the storage tank.
 5. The method as recited in claim 4,wherein the positive pressure is created by using a tap fitting to placethe storage tank in fluid flow communication with the flow line.
 6. Themethod as recited in claim 1, wherein solution is drawn through a pickupfilter positioned in the bottom portion of the storage tank.
 7. Themethod as recited in claim 1, wherein air is vented from the storagetank into the flow line via a vent port.
 8. The method as recited inclaim 7, further comprising drawing from the top portion of the storagetank via the vent port a portion of the fluid in the storage tank. 9.The method as recited in claim 8, wherein the vent port is sized todetermine a mix ratio of the fluid drawn from the top of the storagetank and the solution drawn from the bottom of the storage tank.
 10. Themethod as recited in claim 7, wherein a portion of the fluid from theflow line is diverted into a top portion of the storage tank via aninlet port.
 11. The method as recited in claim 1, further comprisingdiverting a portion of the fluid from the flow line to the solutiondrawn from the bottom of the storage tank using a crossover connectionthat is positioned between the inlet port and the outlet vent.
 12. Themethod as recited in claim 11, further comprising using a mixing valvepositioned within the crossover connection to control the amount offluid diverted into the top portion of the storage tank.
 13. The methodas recited in claim 1, wherein solution is drawn from the bottom portionof the storage tank with as little as two gallon per hour flow in theflow line and as little as five PSI operating pressure within the flowline.
 14. The method as recited in claim 1, further comprising using aflow restrictor within the flow line for controlling an amount of fluiddiverted from the flow line.
 15. The method as recited in claim 1,wherein a negative pressure in the flow line is utilized for drawing thesolution from the bottom portion of the storage tank.
 16. The method asrecited in claim 15, wherein the negative pressure is created by using atap fitting to place the storage tank in fluid flow communication withthe flow line.
 17. The method as recited in claim 1, further comprisingequalizing pressure within the storage tank with pressure in the flowline using fluid diverted from the flow line.
 18. The method as recitedin claim 1, wherein solution is drawn from the bottom portion of thestorage tank at a rate consistent with a rate of fluid flow in the flowline.